The present disclosure relates generally to a bearing assembly and, more specifically, to a contamination-resistant bearing assembly having a multi-part sealing structure particularly useful in harsh environmental conditions such as agricultural tillage applications.
Contamination problems are particularly apparent in agricultural tillage implement bearings because such bearings operate in wet and muddy soil conditions and therefore are exposed to contaminants such as dirt, mud and water. Extended bearing usage in such environments often allows dirt and mud to accumulate and pack against the sealing structure and lead to contaminant ingress into the bearing space and eventually lead to bearing failure. Oftentimes, several times a year such bearings may be exposed to high pressure washing and during such cleaning process contaminants are often forced into the bearing space. Once a bearing is contaminated, the bearing will eventually seize and fail to turn or become loose due to wear and corrosion.
Typically, the life of bearings used in these harsh environments is sustained through frequent and plentiful relubrication to purge the bearing assembly of contaminants and avoid corrosion of the bearing space and rolling surfaces. However, maintenance-free bearings cannot be easily lubricated, and therefore the foreign material typically cannot be flushed away.
Bearing assemblies used in agricultural tillage implements also have to allow for dynamic misalignment to accommodate deflections encountered during the tillage operation. The inability of a bearing assembly to misalign results in high internal stresses which lead to accelerated bearing failure. Current assemblies allow misalignment wear in key areas resulting in bearing damage after extended operation.
Development of a self-aligning maintenance free unit saves the time and expense of relubrication as well as reduces environmental contamination caused by purging grease during relubrication.